Process of welding metal.



W. M. WHITNEY.

PROCESS OF WELDING METAL.

APPLIOATION FILED MAY 23,1909.

986,528, Patented Mar. 14, 1911.

71 1; 51105565 [nven {for W f h I/Zharnfl WZzi/ney UNITED STATES PAT OFFICE.

I! OF WINOmiDON," MASSACHUSETTE PROCESS" 0!! WELMNG RETAIL lrwlmtlbn t fl Patented Mar.- 1431911. Application filed May 20,1909. ficrlalfflo. 490,004.

To all whom. it may concern:

Be it: known that I,.VV1LI.IAM M. WHIT- may, a citizen of'the United States, residing.

invented a new and. useful Improvementin Processes of Welding Metal, of which the following is a specification.

' My invention relates to a'process of welding metal in which the metals to be welded are of such different degrees of hardness that the amount ofheat required to bring one to the welding heat would be sufiicient to burn the other, thereby renderin it' use-. less intheunion. An exam le of t e weldin of metals possessing 1: ese characteristics is the union of steel possessin as one ingredient tun ten and wrought iron or steel. The we ding of tun ten steel and wrought iron or steel has eretofore been because of the to melt the suramount of heat necessary d b an ring it into face of the tungsten stee condition for welding. The subjection of pieces of tungsten steel and adjacentwrought metal to the weldingheat of the tungsten steel would burn up'or consume the wrought metal. Such union is, however, desirable in the manufacture of cutting tools for wood and metal working machinery, in which the cuttin edge is formed from the tungsten steel-an the remainder of the tool is reinforced by a wrought metal on account of the'extreme brittleness and cost ofthe twigs en steel.

.. invention is, however, applicable to a wel ing of any two metals in which the temperature necessary to melt the surface of one will be sufficient to burn the other. In the accompanying drawings forming. a

part of this specification Figure 1 represents hard and soft metal having their opposing.

surfaces united-to an interposed layerof fused metal.

Similar reference letters and figures refer to similar parts in the different views.

In carrying out my improved process, I

, take a plate of hard metal 1, such'as tungsten steel, which is. to form one member of means of a blow pipe or 'other. suitable method of obtaining an intense heat on a limi-r ted area, I bringasmall portion of'the plate to a weldmg' heat. Ithenapply to the heatedsurface a small quantityof'melted metal,

fusibl'eat a lower degree oftemperaturethan said heated metal. .This may be con veniently-accom lished by introducin (into;

the flame ofthe low pipe a piece ,of sible wrought or, cast metal, preferably. a. soft cast iron, or other materialof a less de ee of hardness than the heated metal. his

the completed toolor other product and, by

fusible metal is held in the heat'untilit is melted and a portion of .it has been deposited upon the heated surface of the hard metal as shown at 2, Fig. 1. As these two bits of metal are bothata weldingpoint, the small drop of the softer metal is united to the heated areaofthe harder metal from which the heat of a blow pipe is removed before the softer metal is-burned. This process is continued drop by drop until the entire surface ofthe plate of tungsten steel, or other hard metal, is covered with a series of individual' pieces of the softer metal each welded to the heated plate. When this has been accomplished, the plate 3' of wrought iron or steel, which is desi ed to form the backing, is laced upon t e' sur-' face of the softer meta such as cast iron applied. in a fused state, as above described,

and already securely united to the harder plate. The plates are then heated to the welding heat. of the softer metal and the backing plate is united by. compression to the metal which is already welded to the harder plate. The result is a combination of the particles of the intermediate fusedmetal '2 with the particles of'the metal backing 3, and as the intermediate metal has already been combined. with the particles of the harder plate, the wrought metal backing becomes firmly unitedthereto.

Any means of melting the softer metal which is tobe applied to the harder plate may be employed, the only essential being that it be applied to the harder plate in a melted condition and in small quantities upon the restricted areaof the harder plate which has been heated to the welding point. In some cases where the harder plate is very thin, the intense heat of the blow pipe would tend to distort the plate as it is heated. T o

the plate in such cases thicker and narrower than its final shape and, after the melted softer metal has been a plied, I compress, by rolling or otherwise, t e plate to its final form. This also levels the surface of the softer fused metal, which is left uneven and of varying thickness as a result of 1ts ap l1- cation in small quantities. As the so ter metal is applied to the harder platein a fused condition, the particles are granular and do not furnish the additional strength which is the object of the welding thereto of the softer but tougher metal. The requisite toughness is obtained by the addition of the plate of softer metal which is not melted, but is brought merely to the welding omt. The metal 2 applied in a melted con it-ion directly to the heated surface of the harder plate 1 acts merely as a bond of union between the harder plate 1 and the softer metal backing 3.

The principle of operation is to so arrange the heating of the harder steel and the softer metal that, while the harder plate is brought up to its welding temperature, the softer metal shall not be heated beyond its melting temperature. The heated harder metal and the fused softer metal are thus brought together and their particles allowed to commingle, without injuring the softer metal by the intense heat required to bring the harder metal to the Welding point. A further addition of wrought metal to give the required toughness is now possible owing to the thin coating of soft metal which is now integral with the plate of harder metal.

When a blow pipe is used to impart the necessary heat to bring the harder plate to the welding point, the softer metal to be melted is introduced into the flame of the blow pipe at the proper time to cause the melting of the softer metal simultaneously with the arrival at the welding heat of the harder metal.

The union between the melted metal and the plate of harder metal may be produced without compression, but when the plate of softer metal is applied to the surface of the metal which has been fused, pressure is applied as in the ordinary process of welding.

In the above description of my process, I have used the terms hardness and softness with reference to the comparative fusibility of the metals treated; the metal fusible at a high degree of heat being considered as a hard metal, and that fusible at a lesser degree of heat as a softer metal.

I claim,

1. A process of welding metals of such different degrees of hardness that the heat required to melt one would be suflicient to burn the other, comprising covering the. surface of the harder metal, heated to a weld ing point, with melted metal fusible at a lower temperature than said harder metal and welding a plate of softer metal to the surface so prepared.

2. A process of welding metals of such different degrees of hardness that the heat required to melt one would be sufficient to burn the other, comprisin heating restricted areas of the surface 0 the harder metal to a welding point, applying to each heated area a limited quantity of melted metal 'fusible at a lower temperature than said harder metal, heating said prepared surface to a welding point and welding thereto a heated plate of said softer metal.

3. A process of weldin metal in order to apply to a hard and britt e metal a soft but toug er metal as a backing, com rising heating in succession limited areas o the surface of a plate of brittle metal to the weldin point, applying to each area as it is heate melted metal having a meltin point at a lower temperature than said grlttle metal and welding to said surface a plate of softer material than said brittle plate.

4. A process of welding metals of such different degrees of hardness that the heat required to melt one would be suflicient to burn the other, comprising covering the surface of the harder metal, heated to a welding point, with a thin coating of melted metal fusible at a lower temperature than said harder metal, heating a plate of softer metal to the weldin point and uniting the surfaces of said so er metals by compression.

5. A process of welding metals of such different degrees of hardness that the heat required to melt one would be suflicient to burn the other, comprising heating the surface of said harder metal to a welding point, uniting with the particles of said surface melted metal fusible at a lower degree of temperature than said hard metal, and uniting with the particles of said melted metal the surface of a softer metal heated to a welding point.

WILLIAM M. IVHITNEY.

Witnesses:

PENELOPE COMBERBACH, RoY D. TOLMAN. 

